User API questions

[D X]

I'd like to do some load/performance/cost testing on real App Engine servers (not dev_appserver) and I have a few questions about the User API. 

1. Is it possible for me to log in using a non-browser user agent, ie a python app using the Requests python library or using Apache JMeter?  

2. I'd like to simulate behavior with 100 or 1000 users.  Is it possible to generate test google accounts to log in with?

3. When I logout via the User API, it seems to log me out of every Google service in every open tab.  Ie if I'm logged into Gmail and Google Drive, and I log out of my app, I'm logged out of Gmail and Google Drive as well.  Is it possible to logout of only my app?